Triple salt and method of making same.



UNITED 'STATES PATENT OFrIcE.

EMIL O OURANT, OF BERLIN, GERMANY.

TRIPLE SALT AND METHOD OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 693,378, dated.February 18, 1902.

Application filed August 15,1899. Serial No. 72 7,297. (No specimens.)

T0 at whom it may concern.-

Be it known that I, EMIL COURANT, doctor of philosophy and chemist, asubject of the- King of Prussia, Emperor of Germany, residing at Berlin,Germany, have invented certain new and useful Improvements in TripleSalts and Processes of Producing the Same; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

The present invention relates to. the production of triple saltscontaining double cyanids. The double cyanid compounds, such as calciumsilver cyanid or barium nickel cyanid, are Very unstable compounds. Ihave discovered that salts may be obtained of a great stability fromthese compounds when treated in alkaline solution with an acid.

In carrying out my process the silver triple salt, for example, may bemade as follows: Pure silver oxid is dissolved in a solution of bariumcyanid in such proportions that one molecule of oxid of silver (Ag O) isreckoned for two molecules of barium cyanid (2BaOy t'. e. the proportionof two hundred and thirtytwo parts, by weight, of oxid silver for threehundred and seventy-eight parts, by weight, of cyanid of barium insolutionso as to form the soluble body Ag Oy -BaGy BaO, or bydrate ofbarium may be added to a solution of the double salt Ag Oy -BaGy inproportion of one molecule of the hydrate to one of the double salt. Thecompound thus formed is treated with an acid,such as hydrochloric acid,whereby the triple salt Ag Gy BaOy BaOl is obtained. It is to beobserved that the acid is not employed in surplus. An amount of freeacid would decompose the compound. It is best to introducethe acid intothe liquid from below by means of a pipe. In like manner other triplesalts may be produced.

' In this specification the term triple salt containing a double cyanidis employed to signify asalt consisting of a combination of v a cyanidof an alkaline metal or alkaline-earth metal (such as barium, &c.) withthe cyanidof another metal and with a salt (other than cyanid) of thesaid alkaline metal or alkalineearth metal. Such salt combinationconsists, therefore, of three saltsna'mely, of two cyanids and of a saltother than cyanid. Such triple-salts may practically be used aselectrolytes for the purpose of electrolytically precipitating the metalcontained in one cyanid of the triple-salt combination. If, for example,it is intended to precipitate copper upon another metallic article,(such as a zinc arti cle,) a solution containing, perhaps, three to tenper cent. of the copper triple salts (Cu Cy eLKCyK SO is employed as theelectrolyte, using an anode of metallic copper and the zinc article ascathode. Since such triple salts are stable, they canbe previously manu=factured or stored.

In the following claims I use the expression metal of the alkalinegroups to mean an alkaline metal or an alkaline-earth metal.

I claim as my invention I I 1. As a new article of manufacture a triplesalt containing a double cyanid and consisting of a combination of acyanid of a metal of the alkaline groups with a cyanid of another metaland a salt, other than cyanid, of the said metal of the alkaline groups,substantially as described. I o

2. The process herein described of producing a triple salt with a doublecyanid, said process consisting in causing a metal oxid to react withcyanids of a metalof the alkaline groups and subjecting the product tothe ac- EMIL} COURANT.

Witnesses:-

MAX. 0. STAHLER, HENRY HASPER.

